The present invention relates generally to the field of dental implants and, in particular, to new and useful soft tissue preservation abutment arrangement and method with immediate implant placement. The invention relates generally to the ability to record the spatial relationship of the residual soft tissue socket of an extraction site, to the position of an immediate implant placed within the alveolar bone without direct contact of the structures. The invention relates generally to recording the individual shape and position of the residual soft tissue socket and how it relates to other structures prior to removal of the tooth, namely the shape and position of the clinical crown of the extracted tooth and the occlusal contact of the opposing and adjacent teeth.
General Considerations and Problems to Overcome:
The tooth is a structure of the oral cavity which is vital to the capability of chewing and important to the general well-being and appearance of people. Anatomically, the tooth resides within the oral cavity, firmly anchored within the upper and lower jaws (maxilla and mandible). Human teeth reside within two distinct anatomic regions of the jaws; the apical inferior portion of the tooth (the root) is connected to the jaw via an attachment called the periodontal ligament. We will here define this portion of the tooth that is connected to the bone as the “bone-zone” or hard tissue zone of the tooth. Second, the superior portion of the tooth (the anatomic crown) is connected to the jaw in the soft tissue or gingival region of the jaw defined as the “tissue-zone” or soft tissue zone. The anatomic crown is demarcated, as that portion of the tooth superior to crest of bone and it will include a small portion of the root superior to the crest of bone as well as the clinical crown that is visible. The tissue-zone forms a soft tissue collar around the neck of a tooth. This tissue-zone connection (i.e. soft tissue to tooth attachment) is composed of gingival fibers that insert into the superior aspect of the root surface; specifically, hemidesmosmal cell attachment to the root and crown forming a biological adhesion of the sulcular epithelium (gingival tissues) to the surface of a tooth.
The tissue-zone connection plays a critical role in maintaining health of the oral cavity. It does this by preventing the ingress of microbes and foreign substances into the body by providing a “biologic-seal” at the interface of the tooth-jaw connection at the tissue-zone. This functional attachment of the soft tissue to the surface of the tooth should be fully appreciated as a critical defense barrier. As without the presence of this soft tissue biologic seal the underlying bone would be vulnerable to numerous invasions of various foreign substances.
In addition, the tissue-zone plays an essential role in maintaining and preserving the dental esthetics of the smile. This same tissue-zone represents the peaks (papillae) and valleys of the soft tissue gingival that surround the neck of each and every tooth. It is the spatial relationship of tooth form and color with healthy soft tissue gingival architecture that are known as the essential building blocks of dental esthetics as we know it. Experts of dental esthetics have called the soft tissue gingiva “the frame” of the picture, and regard the teeth as the “subject matter” of that painting. Disregarding the frame of a painting would certainly impact the overall esthetic appearance being viewed, and the same is true with respect to the gums and teeth. The loss or the alternation of anatomic structures of the tissue-zone has been shown to lead to an inferior esthetic outcome in addition to causing a potential risk of disease for the patient.
The tooth and its attachment to the jaw is subject to numerous pathogens over the lifetime of a patient, particularly due to trauma/fracture, endodontic failure, decay, localized periodontal disease, etc. Any of these conditions can lead to the eventual need for removal of either a single tooth or multiple teeth. The removal or extraction of a tooth or teeth will result in a radical morphologic change to the anatomy as well as the potential exposure of the internal tissues (connective tissues and underlying organs) of the body to invasion by foreign substances.
The extraction of a tooth results in a cascade of changes depending on how this procedure is performed. Tooth removal in the past has been a highly traumatic surgical procedure. It was not uncommon for an oral surgeon to fully reflect the gingival tissues as a surgical flap to expose the underlying tooth and bone to aid in the ease of access and visualization of the tooth to be removed. It is during this surgical reflection of the gingival soft tissues that the normal anatomy of the tissue-zone would be radically altered and permanently changed. Destruction of the normal architecture of the gingiva occurs as surgical instruments were used to cut, tear, crush and rip the attachment fibers between the tooth and soft tissues of the tissue-zone. In accordance with gingival surgical flap surgery, closure of a surgical flap is accomplished with the placement of sutures to close the wound created. Primary (or complete) flap closure is highly desirable to ensure the re-establishment of a biologic-seal of the soft tissue to preventingress of foreign bodies to the host.
Gingival flap surgery also has the known deficiency to result in bone loss from the stripping away of the periosteum and hence the blood supply to the bone during the reflection of a surgical flap. It is well documented in the dental literature that gingival surgical flaps result in bone loss by the exposure of the underlying bone. Dr. Lindhe and co-workers have scientifically demonstrated that surgical flap elevation and removal of teeth leads to loss of the residual bone and the shape of remaining ridge after tooth removal. These undesirable anatomic changes to the bone make the placement of implants more complex and increases risk for patients.
For the reasons identified above, the trend toward minimally invasive surgical procedures has been developed toward the extraction of teeth. Examples of these changes include the use of micro-surgical instruments, periotomes and extraction forceps that do not require the reflection of a surgical flap to remove teeth. Ultrasonic (piezo technology) surgical instruments, dental lasers and rotary devices have been suggested as mechanisms to minimize trauma during the removal of teeth. It is generally accepted within the profession that a minimally invasive technique for tooth removal should be the standard of care.
In an attempt to minimize detrimental anatomic changes during the surgical removal of a tooth, a major effort is now underway to preserve the bone-zone and tissue-zone after tooth removal. The objective of the dental profession to preserve bone was a natural extension of a vast body of knowledge recently created on periodontal bone regeneration via the use of bone replacement substances. Examples of such efforts include autografts, allografts, xenografts and a variety of bone replacement materials that include; Bone Morphogenic Proteins (BMP's), Stem Cell Derivatives, Platelet Rich Proteins (PRP's) derived from the blood and numerous other biologic sources. Bone regeneration after periodontal disease is well established in the prior art. A deficiency of using bone replacement substances is the inability to contain and protect these materials to exposure to the oral cavity during the critical healing phase, i.e. a fundamental inability to re-establish the all-important biologic-seal of the Tissue-Zone once a tooth is removed.
The use of barrier membranes for guided tissue bone regeneration (GTR) is a known attempt to preserve and regenerate lost bone after periodontal disease. The use of membranes has more recently been applied to the regeneration and preservation of bone after tooth removal. Barrier membranes assist in creating a protective barricade to the bone-zone by excluding unwanted cells (connective tissue cells) from the healing site. This is an attempt to allow the body to more effectively refill a residual bony socket with bone cells (a.k.a. osteoblasts) known to be critical for bone growth. A general deficiency of using barrier membranes is the direct exposure of a barrier membrane that consequently lends to the inability to establish a soft tissue seal. The exposure of the barrier membrane leads to plaque accumulation on the surface of the membrane that is impossible to clean. Once membranes become exposed to the oral environment, bacteria colonization on the surface of the membrane quickly spearheads an infection and/or failure of regeneration of bone. The primary cause of the exposure of the membrane is a lack of a soft tissue biologic-seal after gingival flap surgery. The inability to re-establish a biologic-seal after the removal of a tooth has many repercussions to bone and soft tissue regeneration.
A general deficiency of the fresh extraction site is the ability to relate the position of the overlying residual soft tissue to an implant placed immediately into a fresh bony extraction site. The root socket will often dictate where and how the implant will be placed. An angle naturally exists between the clinical crown and the root of a tooth ranging from 5 to 28 degrees in a buccal-lingual direction. Teeth are also known to have a medial or distal tip of the root within the range of 2 to 17 degrees in a properly aligned dentition according to the Kraus, Jordan and Abrams Dental Anatomy and Occlusion textbook. See Kraus B, Jordan R, Abrams L., Dental Anatomy and Occlusion, Waverly Press, Inc. Baltimore, Md. 1980. Teeth are often mal-aligned prior to removal and may therefore have root positions with greater angles then those previously mentioned. It is therefore not uncommon that the roots of these teeth would require an immediate implant to be positioned with a significant angulation to the ideal axial position resulting in an angulated post-implant placement. Additionally, the ability to control the vertical, horizontal and transverse positioning of an implant by the operator during immediate implant placement into an extraction site can be difficult as it is often dictated by the remaining bone availability. Bone morphology related to the overlying gingival tissues are considered independent anatomic structures in which the shape and position of one does not dictate the other. This finding is why pre-treatment dental CT-scans are considered the standard of diagnostic care for implant placement. Therefore the location of an immediate implant placed within a fresh extraction site is typically not positioned concentric to the position of the overlying residual soft tissue gingival socket opening. There is typically a discrepancy between the vertical, horizontal and transverse positions of the opening of the soft tissue gingival socket and the axial position of the immediate dental implant so much so that current available implant components are ineffective.
A general deficiency of being able to relate the spatial position of the residual soft tissue gingival socket complicates the ability to fabricate a dental prosthesis from prefabricated “stock” components. The need to utilize customized components to compensate for the disharmony is important to recognize. The independent spatial relationship of the underlying bone (or dental implant) to the overlying gingival tissues becomes difficult or impossible to relate to one another once the tooth is removed. To overcome these discrepancies, the invention will describe a method and device to accurately record the three-dimensional position of the soft tissue gingival socket after a tooth has been removed. It will also describe a method to relate this soft tissue gingival socket to a dental implant placed within the alveolar bone of an immediate extraction/implant surgical placement procedure. Additionally, the invention will describe means to relate the residual soft tissue socket of the gingiva to the position of the extracted clinical crown prior to removal and the occlusal contacts of that crown to the adjacent teeth as well as the opposing teeth, prior to removal. All of the defined relationships are critical to enable the successful fabrication of a dental implant prosthesis.
Loss of the biologic-seal of the tissue-zone also has a significant impact on soft tissue changes to both the macro- and micro-anatomy of the gingiva. It is accepted in the dental literature that the loss of gingival attachment within the tissue-zone leads to the irreversible loss of the interdental papillae and the gingival architecture surrounding a tooth. There are currently no predictable surgical techniques available to correct the gingival changes to vertical height and horizontal dimensional after tooth removal. Much effort has been directed toward preserving the bone after tooth removal but far less effort has been applied to preserving the macro- and micro-anatomy of the tissue-zone after tooth removal.
As will be explained more fully in the following, the method and arrangement of the present invention are effective means to preserve the esthetic and anatomic architecture of the tissue-zone after tooth removal and to relate and record the spatial relationship of this preserved soft tissue socket to the immediate placement of a dental implant. Furthermore, the invention relates the residual soft tissue socket to the position and shape of the extracted tooth as well as the adjacent and opposing teeth.
The understanding of using a minimally invasive technique as well as re-establishing a biologic-seal after tooth removal has been discussed but has not yet been made possible in all cases by known methods and apparatuses. In addition to these important concepts one further concept related to tooth removal is the technique of immediate dental implant placement after the extraction of a tooth/teeth and the ability to relate the anatomic and dental implant structures to one another and to the surrounding teeth.
The replacement of a tooth by a dental implant device is well known in the prior art. It is understood that there are two basic components to the dental implant device; the root-form component held within the bone-zone commonly referred to as the “dental implant” and a second component, the implant anatomic crown composed of an abutment and clinical crown. Both the abutment and clinical crown are typically placed superior to the crest of bone therefore within and superior to the tissue-zone. An implant prosthesis was first described as a surgical method and device that used a fully submerged, non-loaded healing period prior to the connection of the dental implant crown.
The advent of contemporary implant dentistry was first described by Prof. P. I. Branemark in the late 1970's and established the use of a titanium root-form screw to be inserted into the bone placed by using an atraumatic surgical technique described by this researcher/inventor. The method described by Branemark discussed the placement of the dental implant into jawbone of a fully edentulous ridge. He described a method in which the implant would be fully submerged and non-loaded during a healing period of 4-6 months after the dental implant was placed and covered within the bone. Pre-operative conditions therefore required a fully healed ridge in which teeth were previously removed. The method of using a submerged, non-loaded healing period for dental implants remains an approach still widely utilized today.
However, over the past 30 years alternative methods to implant placement have occurred. The following are different methods that have been advocated to the non-submerged, non-loaded implant healing technique.
Advantages and disadvantages will be briefly discussed for each technique.
Delayed, Submerged, Non-loaded Implant Placement Method:
Defined as the method for placing a root-form dental implant into the jawbone. The implant is placed within the bone-zone initially. The pre-operative condition requires an edentulous ridge. The technique describes the placement of the implant into the bone at or below the crest of bone and it is fully covered by primary flap closure. An initial healing for a period of 4 to 6 months is required. A second surgery is required to expose the root-form implant and to connect a healing abutment. Second healing period of 2-3 months is required for soft tissue. Final crown delivery occurs approximately 9 months after the start of treatment.
Deficiencies of this Prior Art Method:
1. Multiple surgeries prior to implant crown placement are required.
2. Requires an edentulous ridge prior to implant placement into the bone-zone resulting in the irreversible changes to the soft tissues of the tissue-zone.
3. Difficult to re-establish a biologic-seal after numerous surgeries and the connection of the implant crown.
4. Increased cost because of multiple surgeries and prosthetic components.
5. Inability to retain the pre-existing soft tissue anatomy prior to tooth removal soft tissue healing results in undesirable changes to the overlying gingival tissues that result in dramatic changes and/or reduction in the height and shape of the interdental papilla. These changes lead to open contacts, open embrasures and affect the final dental implant prosthesis. The resulting open spaces collect food, dental plaque and calculus and put the patient at greater risk to losing additional teeth in the future.
6. An inability to maintain and record the position of the pre-treatment soft tissue gingival anatomy found prior to tooth removal to the underlying alveolar bone and after a tooth has been removed. This positioning of a dental implant is dictated by bone availability with a failure to be able to relate the position of the dental implant to ideal pre-treatment gingival tissues. The delayed approach makes it impossible to position the dental implant relative to vertical, horizontal and transverse, i.e. X, Y, Z axes of the soft tissue opening prior to tooth removal.
Delayed, Non-Submerged, Non-Loaded Implant Placement Method:
Defined as the method for placing a root-form dental implant into the jawbone exemplified by the Straumann, ITI implant company. The implant is placed within the bone-zone initially. The pre-operative condition requires an edentulous ridge. The technique describes the placement of the implant into the bone at or below the crest of bone or within the tissue-zone. A transmucosal healing cap component is used. A healing abutment or “cap” is placed onto the implant that is in direct contact with the soft tissue during the initial bone-healing period of 4 to 6 months. A second surgery is not required to expose the root-form implant. Reformation of the tissue-zone is required. A connection between the implant and the healing abutment is within the tissue-zone.
Deficiencies of this Prior Art Method:
1. Requires an edentulous ridge prior to implant placement into the bone resulting in the irreversible changes to the soft tissues of the Tissue-Zone.
2. Requires flap surgery to place dental implant
3. Difficult to re-establish a biologic-seal after surgery and the connection of the implant crown.
4. Difficult to re-establish soft tissue anatomy to the state it was prior to tooth removal.
5. Healing abutment has a connection interface within the Tissue-Zone, which allows bacteria to adhere impeding wound healing.
6. Increased cost because of multiple components.
7. Loss of the natural anatomic gingival contours after healing of the extraction socket making it difficult if not impossible to identify and record the spatial position of the residual soft tissue gingival to the position of the underlying bone and/or dental implant.
Immediate Root-Form Implant Placement:
A recent trend in implant dentistry that has occurred, that overcomes the deficiency of requiring multiple surgeries, is the immediate placement of a root-form dental implant directly into an extraction socket after tooth removal.
This method deviates from the original protocols established by Branemark and co-workers. The advantage to the simultaneous placement of a root-form dental implant after tooth removal is the reduction of the number of clinical procedures required as well as decreased treatment time. This technique eliminates the need to have the bone ridge healed after tooth removal consequently requiring fewer surgical procedures.
Immediate implant placement requires a mechanical locking of the root-form dental implant into the residual socket-site after a tooth has been removed. Mechanical locking refers to the root-form implant engaging undisturbed bone in an attempt to provide primary mechanical stability of the implant within the extraction socket. Immediate implant placement is highly desirable in comparison to delayed implant placement since it allows the immediate replacement of the tooth at a substantially reduced amount of time when compared to previous method of delayed implant healing.
Immediate implant placement also requires the positioning of a root-form implant to be located into the residual bone socket dictated by the previous position of the root of the tooth. As previously described the root of a tooth has a naturally occurring angle formed between the root axis and of the crown axis of a tooth. There are angles in two orthogonal planes, the anterior-posterior and transverse, the angle ranges from 5 to 28 degrees in a buccal-lingual direction and 2 to 17 degrees in the mesial-distal direction for tooth/teeth in an ideal position. Frequently roots are found to be mal-aligned resulting in significant deviations to the norm. An extracted root anatomy can have an atypical root form that can be curved, bent or positioned in an unusual location within the bone and the adjacent roots of teeth. Therefore, more often then not the root of a tooth is not axially centric to the clinical crown of a given tooth. Additionally the root of a tooth is not positioned centrically between the two adjacent teeth of the extraction site. In fact more often then not the angulation of the root socket and the soft tissue socket are difficult to align. Therefore, the immediate dental implant is typically not centrically located in relation to the opening of the residual soft tissue socket or the adjacent teeth and roots. Compounding this deficiency is the difficulty of vertical positioning of the immediate dental implant as it is related to the residual soft tissue socket. Vertical discrepancies in position make the positioning of current components difficult if not impossible to use at times since they cannot relate the soft tissue anatomy of the residual soft tissue socket effectively since their shapes and orientations were not designed for the immediate soft tissue socket.
Immediate Implant Placement Presents Numerous Risks and Deficiencies with Current Methods Used:
1. An inability to fully engage the entire remaining socket surface after tooth removal, thereby leaving a space (gap) between the surface of the implant and the surface of the remaining bone.
2. An inability to establish a biologic-seal to the overlying soft tissues after a tooth has been removed.
3. An inability to retain bone regenerative materials if a residual gap remains between the surface of the implant and the bone socket.
4. An inability to establish a biologic-seal of the soft tissue over a barrier membrane to protect and contain bone regeneration materials and the blood clot.
5. Inability to preserve the soft tissue architecture of the gingival of the Tissue-Zone.
6. Inability to compensate for the vertical, horizontal and transverse discrepancy between the positions of the immediate dental implant in relation to the overlying soft tissue gingival socket after tooth removal.
7. Inability to relate the position and anatomy of the residual soft tissue socket to the clinical crown of the extracted tooth and the relative position that the soft tissue socket has to the adjacent and opposing teeth.
8. Inability to record the peaks and valleys of the residual soft-tissue gingival socket as current abutment designs that are not designed to mimic the residual soft tissue socket but are circular in design.
The deficiencies of achieving a predictable and esthetic long term outcome when using an immediate implant placement protocol can all be directly attributed to the inability to establish an acceptable biologic adaptation to create an effective biologic-seal in the tissue-zone of the remaining soft tissue socket after removal of a tooth.
The deficiencies of achieving a predictable and long term esthetic outcome of the final implant prosthesis associated with an immediate implant placement protocol can all be directly attributed to the inability to accurately record the spatial relationship of the overlying soft tissue gingival socket to the underlying dental implant. This non-concentric relationship makes it difficult if not impossible to utilize pre-fabricated stock dental implant abutments in all situations when working with immediate implant placement into a fresh tooth extraction site. Current designs of dental implant abutments are two piece components that require a central hole access for the position of the retaining screw which limits the position of these abutments relative to the dental implant. Current dental implant abutment designs which are anatomic are based on the root anatomy and do not take into account the shape of the residual soft tissue socket topography with a peak and valley gingival margin, hence positioning, maintaining and recording the residual soft tissue socket anatomy is difficult if not impossible with the current “anatomic root form designs” of dental implant abutments. Additionally, lack of an ability to record the spatial relationship of the tissue-zone (trans-gingival zone) of the soft tissue socket to the adjacent teeth and opposing arch make it difficult if not impossible to pre-fabricated stock dental implant abutments.
The tissue-zone, i.e. the residual soft tissue gingival socket, represents the critical transition zone between an immediate dental implant and what will be the shape and position of the final implant crown prosthesis. This unique transition zone must compensate for the spatial position of the implant contained in bone and the implant crown in the oral cavity. The tissue-zone (trans-gingival zone) of the gingiva must be considered an independent anatomic structure when compared to the root-form implant and to the position of the clinical crown. Compensation of positioning can only be achieved if the components used to record this structure are independent from both the root-form implant and the clinical crown of the implant prosthesis owning to the natural and avoidable occurring vertical, horizontal and transverse discrepancies.
Immediate implant placement of a root-form dental implant has been shown to effectively osseointegrate by numerous authors (reference included herein). The residual gap that is present between the implant surface and the bone surface requires careful management whether a surgical flap is performed or a non-flapless minimally invasive extraction technique is used. In either of these two approaches, irreversible soft tissue changes have been shown to occur with immediate implant placement after tooth removal. Changes within the tissue-zone are shown to occur as early as 2-3 days after the immediate implant placement.
Other Prior Art:
U.S. Pat. No. 5,417,568 to Giglio discloses a dental prosthesis that is said to accommodate the gingival contours surrounding the implant prosthesis by imitating the gingival contours around natural teeth. Since the abutment is rigidly connected to the implant and must always be axially aligned with the long axis of the implant, the abutment will rarely, if ever, closely engage the entire existing soft tissue socket created when a tooth has been extracted; consequently, inadequate soft tissue socket adaptation exists. Moreover, seldom is the axis of the implant exactly aligned with the axis of the soft tissue socket. Also, although the abutment disclosed by this patent has raised ridges around its outer perimeter, it is symmetrical, and therefore does not mimic the asymmetric anatomy of a soft tissue socket in the gingiva of a patient from whom a tooth has been extracted.
U.S. Pat. No. 5,899,695, Lazzara, et al. discloses an interchangeable healing abutment and impression coping that is described as an anatomic root form but fails to describe a means of preserving and/or relating the position of the overlying residual soft tissue socket to the underlying position of the dental implant. Components were described to have a rigid snap-fit or direct contact with one another allowing a healing abutment and impression coping to be interchangeable components. Lazzara, et al. also discloses a healing abutment shell in U.S. Pat. No. 5,899,697 that is fitted by seating the shell with a positive contact upon the shoulder of the core component of the dental implant thereby limiting the spatial position of the shell to relative position of the dental implant within the alveolar bone. This requirement sets physical limitations in the vertical, horizontal and transverse positions. The components are shown to be concentrically designed and related to one another and require luting and fixating the components together during use. The overall position of the healing abutment is physically dictated by the position of the dental implant and fixation screw within the root-from implant. The reference discloses no structure for maintaining or preserving the contours of the gingival soft tissue socket with the peaks and valleys of the soft tissue socket. There is no description or teaching as it relates to the non-congruous spatial relationship between the underlying root-form implant and residual soft tissue gingival socket. There is no means to record the spatial position of the residual soft tissue socket to the adjacent or opposing teeth of the extracted tooth. Further, and importantly, these teachings only relate to delayed implant placement, not immediate placement.
U.S. Pat. No. 8,185,224 to Powell, et al. discloses a two piece healing abutment that is to be rigidly connected to a dental implant with positional and orientation markings for the purpose to determine the location of the root-form implant. The healing abutment is connected via screw that retains a healing abutment in direct contact to the underlying root from implant. The reference teaches no structure to maintain or preserve or record the contours of the gingival soft tissue socket with the peaks and valleys of the soft tissue socket. The “anatomic abutment” is based on root form that does not mimic the shape of the soft tissue residual socket topography therefore proper positioning and recording is not possible with this design. The root-form implant is shown to be centric and/or rigidly positioned to the healing abutment with markings. There is no description of a means to relate a non-centric position of the healing abutment related to the root form implant. There is no description or means to compensate or record the independent position of the residual soft tissue socket as it relates to the independent position of the root-form dental implant. The healing abutment is dictated by the position of the root-form implant.
Nowhere in the prior art or in current dental implant wisdom is an anatomically shaped and sized abutment in the form of an asymmetric tubular shell used in conjunction with a dental implant, which is not rigidly or concentrically connected to the implant in advance. As a result of the invention here disclosed, the shell can be moved and maneuvered to any orientation with respect to the x-, y- or z-axis in a soft tissue socket to effectively and fully engage the tissue-zone with no space or gap between the outer surface of the shell and the soft tissue socket, independent of the position and axial orientation of the implant in the bony socket. This independent positioning of the abutment shell and the implant is one of several important advancements of this invention over the prior art.
Additionally, the prior art does not describe a hollow shell with peaks and valleys that mimic that which is found in the residual soft tissue gingival socket anatomy. Current designs that claim to be “anatomic abutments” are designed to mimic the root form related to emergence profile and shape of a cross-sectional root form but this does not mimic the shape that is found after an extraction of a tooth as it relates to the residual soft tissue gingival socket. Prior “anatomic abutments” are designed to be used for a delayed implant placement to create an emergence profile based on the root form of a tooth. The present invention is related to retaining, preserving and recording the fresh extraction soft tissue socket to mimics the gingival contour with the peaks and valleys that mimic the soft tissue contour of a soft tissue socket. The prior art does not define the peaks and valleys as described herein that mimics the residual soft tissue gingival socket. A design without the proper peaks and valleys of the transgingival zone as defined herein lacks the ability to accurately record and maintain these tissues.
U.S. Pat. No. RE37,227 to Brodbeck also disclosed a some-what anatomically shaped abutment but again it is axially fixed to an implant so that there is no freedom of movement between the abutment and the implant but rather they are mechanically coupled to each other when being seated in their respective soft tissue and bone sockets so that the position of one is dictated by the position of the other.
An article titled: “Immediate Placement and Provisionalization of Maxillary Anterior Single Implants: A Surgical and Prosthodontic Rationale,” by Kan at al., Pract Periodont Aesthet Dent, 2000; Vol. 12, No. 9, pps 817-824, discloses the building up of an abutment that is fixed to an implant to better match a soft tissue socket by the addition of autopolymerizing acrylic resin around the abutment by sculpting the outer shape of the otherwise fixed abutment to better fill the soft tissue socket. This technique also fails to recognize the advantage of independently positioning the abutment from the implant. In addition, the tissue-zone collapses immediately upon tooth removal and extrapolation of its contours by the author is required to recreate as close as possible the soft tissue-zone profile.
Another attempt at accommodating the mismatch between an implant oriented in a bony socket and an abutment positioned in a soft tissue socket, is suggested in the June 2009 brochure of BIOMET 3i titled “Ideal Solutions For Immediate Aesthetics” that discloses an abutment-implant combination where the abutment axis is at a fixed but non-aligned angle to the implant axis. Here again there is independent positioning of the abutment and the implant so freedom of orientation is not present.